An American nuclear-capable B-2 stealth bomber has conducted a long-range mission over the Pacific to demonstrate Washington’s “visible commitment” to its Asian allies amid North Korean anxieties and ahead of Donald Trump’s visit to the region.

Just as US Defense Secretary was wrapping up his visit to South Korea Saturday, the US dispatched its state of the art B-2 stealth bomber to fly a long-range mission to the Pacific area of operations.

The bomber which flew out of Whiteman Air Force Base, Missouri practiced maneuvers to “familiarize aircrew with air bases and operations in different geographic combatant commands,” the US Strategic Command said in a statement. CENTCOM, however, failed to detail the flight path of the B-2 bomber.

Washington only said the practice run would enable the B-2 crew “to maintain a high state of readiness and proficiency”and that such missions “validate our always-ready global strike capability and are a visible demonstration of commitment to our allies and enhancing regional security.”

Headquartered in Hawaii, United States Pacific Command (USPACOM) is responsible for the Indo-Asia-Pacific region, an area which encompasses more than 100 million square miles, or over half of the Earth’s surface. It is the largest command of the US forces – with roughly 375,000 military and civilian personnel and 1,100 aircraft at its disposal. USPACOM also directs the operations of the US Pacific Fleet that incorporates around 200 ships split between five aircraft carrier strike groups, enlisting 130,000 sailors and civilians.

The B-2 mission is a prelude to Trump’s Asia tour, scheduled to begin in Japan on November 5. Prior to Trump’s trip, US Defense Secretary James Mattis laid the groundwork for discussions. Speaking after talks with his South Korean counterpart Song Young-moo in Seoul, Mattis made clear that Washington will never accept North Korea as a nuclear state. The US defense chief also said that Pyongyang’s ambitions to acquire enhanced ballistic and atomic capabilities will weaken security in the region.

“North Korea has accelerated the threat that it poses to its neighbors and the world through its illegal and unnecessary missile and nuclear weapons programs. I cannot imagine a condition under which the United States would accept North Korea as a nuclear power,” he said.

Any attack on the US and its allies by North Korea will be defeated by a “massive military response” by the United States and its allies, Mattis affirmed. For now, though, the US is seeking a diplomatic solution to the crisis, Mattis added.

Tension between North Korea and the United States has been steadily building after a series of nuclear and missile tests by Pyongyang and warmongering exchanges between Trump and North Korean leader Kim Jong-un.